A shoe suitable for walking or running up and down a mountain protects the foot from collisions with external objects and protects the foot from a sprain on a slope or a rough terrain. Therefore, a shoe of this type has an upper with a higher rigidity as compared with an ordinary shoe.
An upper with a high rigidity increases the force and the time required for lacing and makes it difficult to evenly distribute the tightening force. In view of such a problem, various lacing structures have been proposed in the art.
First Patent Document: Japanese Laid-Open Patent Publication No. 6-78801
Second Patent Document: U.S. Pat. No. 5,167,084
Third Patent Document: Japanese Laid-Open Patent Publication No. 2-903
Fourth Patent Document: Japanese Laid-Open Patent Publication No. 2005-143954
Fifth Patent Document: US 2005/0126043 A1